Field of the Invention
The present invention relates to a banknote processing apparatus, and more particularly, to a banknote processing apparatus for determining the denomination, identification mark, fitness, and/or authenticity of a banknote.
Discussion of the Related Art
The term “banknote processing apparatus” covers a wide range of devices that count banknotes, such as a banknote counter for automatically counting a quantity of bills, a banknote sorter for sorting banknotes according to their condition and fitness for circulation, a banknote recycler, a counterfeit banknote detector, a check processing apparatus, a banknote deposit/dispensing apparatus and an automated teller machine (ATM). The banknote processing apparatus is designed to process paper money such as banknotes and/or checks. When a user places banknotes in an inlet, the banknote processing apparatus counts the banknotes one by one or sorts them according to a specific criterion, and then discharges the banknotes through an outlet, displaying the count and amount of the banknotes.
It is to be noted herein that banknotes processed in a banknote processing apparatus may be any of cash, bills, bank notes, checks, promissory notes, securities, certificates, media, paper sheets, gift certificates, coupons, tickets, label marks, identifications, and the like in the present invention.
In general, the banknote processing apparatus also determines whether an introduced banknote is authentic or fit for circulation in addition to counting banknotes. For example, the banknote processing apparatus determines whether a banknote is fit (i.e., new, worn, or damaged) or counterfeit. That is, the banknote processing apparatus may count an accurate number of banknotes corresponding to a user-requested money amount to be deposited or withdrawn or determine whether the banknotes are counterfeit, doubled, damaged, or contaminated with foreign materials in a bank office or the like. The counted banknotes may include newly issued ones, old ones, lately-printed crisp ones, wrinkled ones, folded ones, punctured ones, discolored ones, worn ones, taped ones, and the like. Typically, the banknote processing apparatus is provided with an image acquisition unit for determining the authenticity, denomination and/or fitness of a banknote as well as counting banknotes, and executes the said functions by processing image information on banknotes, acquired through the image acquisition unit.
Background art is disclosed in Korea Patent Publication Application No. 10-2007-0107331 (entitled “Paper Money Detector” and publicized on Nov. 7, 2007).
The banknote processing apparatus is equipped with a function of identifying the features or identification marks (e.g., serial numbers) of banknotes in order to count the number of the banknotes and determine the authenticity, denomination, and/or fitness of the banknotes. Conventionally, grayscale images are typically used for banknote counting or identification.
However, some nations use banknotes having almost the same bill design, of which the denominations are distinguished not by design but by color. In this case, it is difficult to identify a banknote by a grayscale image, thereby causing errors in a banknote processing apparatus using only grayscale images. In this context, sensors capable of acquiring color images have gained popularity.
Regarding identification of the serial number of a banknote, as the resolution of the acquired image of the banknote increases, the accuracy of identifying the serial number also increases, and a minimum level or threshold of resolution is identified for reliable identification. Therefore, when a grayscale image sensor is replaced with a color image sensor in the image acquisition unit, if the resolution level is lower in the color image sensor than in the grayscale image sensor, the detection performance of the banknote processing apparatus may degrade. On the contrary, if a grayscale image sensor is replaced with a color image sensor with the same resolution in the image acquisition unit, the scanning time to acquire an image and the amount of data to be processed both increase. As a result, the processing speed decreases, or a higher performance system is required, thereby increasing the fabrication cost of the apparatus.